Gimp-thread-pull-off device for buttonhole-sewing machines.



E. B. ALLEN. GIMP THREAD PULL-OFF DEVICE FOR BUTTONHOLE SEWING MACHINES.

APPLICATION FILED AUGJD. 1917.

Patented Sept. 17, 1918.

,4 TTOR/VEY E. B. ALLEN.

GIMP THREAD PULL-OFF DEVICE FOR BUTTONHOLE SEWING MACHINES. 'APPLICATION FILED Ammo. I917.

1 278, 8 1 7 Patented Sept. 17; 1918.

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UNITED sra'rns PATENT orn on.

EDWARD :B. ALLEN, or nnrnenroar, CONNECTICUT, ASSIGNOR TO THE smear. m

FACTURING COMPANY, A CORPORATION OF NEW JERSEY.

' GIMP-THREAD-PULL-OFF DEVICE FOR BUTTONI-IOLE-SEWING MACHINES.

Specification of Letters Patent.

Application filed August 10, 1917. Serial'No. 185,409.

To all whom it may concern:

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Bridgeport, in the county of F airfield and State of Connecticut, have invented certain new and useful Improvements in Gimp- Thread-Pull-Off Devices for, Buttonhole- Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates particularly to buttonhole sewing machines having gimpthread guiding means adapted to lay a gimpthread about a buttonhole as it is being stitched. The gimp-thread, in accordance with the customary practice, runs from a supply-spool or cop stationed at the base of a spool-stand in rear of the machine and extends over an elevated guide carried by said spool-stand and thence downwardly and forwardly through suitable guides at the side of the machine-frame and, laterally, into said frame in proximity to the lower elements of the stitch-forming mechanism. Within the machine-frame a gimp-thread usually traverses a more or less tortuous course through suitable guides in its passage up to the apertured throat-plate or button which guides the thread within the range of action of the stitch-forming mechanism.

It has been found that the slight drag often imposed upon the gimp-thread by the supply spool as the thread is being unwound from the latter, greatly retards the free passage ofthe gimp-thread through the guides on the machine, and causes said guides to impose an excessive drag or friction upon the gimp-thread so that it canonly with great difficulty be pulled through the guide at the stitching point. This excessive drag on the gimp-thread is particularly undesirable as it results in imperfections in the finished buttonhole, such as a reduction in the size ofthe eyelet-end or other distortion of the normal shape of the buttonhole. Also, when the work is shifted to a new stitching position, the previously stitched buttonhole must resist the pull exerted on the gimpthread to draw it through its guide at the stitching point. Excessive friction or drag on the gimp-thread at this time results in further distortion of or injury to the buttonhole.

Heretofore, to obviate these difficulties, it hasbeen customary for the operator to catch the gimp-thread at the rear of the machine,

between stitching operations, and pull a small quantity of the thread from the supply. This action by the operator, however,

is tiring and results in the loss of much sewing machine with a gimp-thread measuring or pull-off device comprising relatively movable glmp-thread engaging devices and have provided actuating means therefor controlled by a moving part of the machine, so that the operator thereof is entirely relieved of the necessity of attending to the slackening of the gimp-thread.

In the accompanying drawings, Figure 1 illustrates the base-portion of a buttonhole machine of a well-known type embodying the present invention. Fig. 2 is a rear endelevation of a portion of the machine-frame showing the pull-ofl applied thereto. Fig. 3

is a perspective view of the pull-ofi' guidebracket. Fig. 4 is a perspective view showing the course of the gimp-thread adjacent the stitching point.

In the present instance, the invention is embodied in a sewing machine of the typeadapted to stitch buttonholes-in leather as more fully represented in my Patent No. 1,048,786, dated December 31, 1912, and in the application of E. B. Allen and B. F. Crosby Serial No. 106,761, filed June 30, 1916. The machine frame is formed with a hollow base 1 from which rises a standard 2 supporting the usual superstructure. including the reciprocating needle 3, which cooperates with lower stitch-forming means of any desired type such, for example, as represented in said Allen and Crosby'application, disclosing the lower curved needle 4. The machine is equipped with the usual buttonhole cutting mechanism including the traveling fulcrum block 5 for the cutter er 5 and which 1 99 and s tter- Patented Sept.'17, 1918.

deliver gimp-thread to the stitching point within the range of action of said stitchforming mechanism, and a gimp-thread pull-ofi" including relatively movable threadengaging devices'adaptedto engage the gimpthread between said gimp-thread-guide and the supply, and an operative connection between a moving part of the machine and at least one of said devices, whereby a free supply of slack gimp-thread is available during stitching or work-shifting operations.

4. In a buttonhole sewing machine, in combination, stitch-forming mechanism, work-supporting means, a gimp-thread guide adapted to deliver gimp-thread to the stitching point within the range of action of said stitch-formin mechanism, and an automatic gimp-thread pull-ofl" device adapted to engage the gimp-thread between said gimp-thread-guide and the source of supply.

5. In a buttonhole sewing machine, in combination, stitch-forming mechanism, work-supporting means, buttonhole cutting mechanism, a gimp-thread guide adapted to deliver gimp-thread to the stitching point within the range of action of said stitchforming mechanism, and means controlled by the action of the machine and engaging the gimp-thread between said gimp-thread guide and the supply for measuring ofi' enough gimp-thread for the next stitching operation.

6. In a buttonhole sewing machine, in combination, stitchforming mechanism, work-supporting means, buttonhole cutting mechanism, a gimp-thread guide adapted to 7. In a buttonhole sewing machine, in

combination, stitchforming mechanism, work-supporting means, buttonhole cutting mechanism including a cutter-shaft making a single rotation during each buttonhole producing cycle, a gimp-thread guide adapted to deliver gimp-thread to the stitching point within the range of action of said stitchforming mechanism, and a gimp-thread pull-off device operatively connected to said cutter-shaft.

8. In a buttonhole sewing machine, in combination, a cutter-shaft, a crank carried thereby, a gimp-thread pull-ofi bar apertured at one end and at its opposite end connected to said crank, and a guide member cooperating with said pull-off bar.

9. In a buttonhole sewing machine, in combination, a cutter-shaft, a guide-member formed with a guideway, and a pull-ofi' implement fitted to slide in said guideway and connected with said cutter-shaft.

10. In a buttonhole sewing machine, in combination, stitchforming mechanism, button-hole cutting mechanism including a cutter-shaft, and a gimp-thread pull-off implement deriving-motion from said cuttershaft.

In testimony whereof, I have signed my name to this specification.

EDWARD B. ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

